For example, Patent Documents 1 and 2 describe arrangement of a well of a memory array of a dynamic-type RAM. Specifically, in a p-type substrate or a deep well, a p-type well is formed to be adjacent to both sides of an n-type well, an n-channel-type MOSFET such as a selective transistor of a memory cell or a sense amplifier is formed in the p-type well, and a p-channel-type MOSFET such as a sense amplifier is formed in the n-type well. Also, Patent Document 2 describes arrangement of wells of a peripheral circuit and an input/output circuit of a memory array of the dynamic-type RAM. Specifically, an n-type well and a p-type well each having an elongate shape whose longitudinal direction is a direction in which a word line extends are alternately arranged along a direction in which the word line is arranged.